1. Field of the Invention
The present invention relates to a coating composition for a soft feel coating on portable terminals and electronic instruments, and to a method for preparing the same coating composition.
2. Description of the Related Art
In general, a resin composition for a soft feel coating has been used for cosmetic containers, golf balls and portable terminals. Most of such resin compositions for a soft feel coating are based on polyester polyol or polycaprolactone polyol.
Generally, the coating composition used in the aforementioned articles consists of a primer composition and a topcoat composition because a polyol-based coating composition of the topcoat shows poor adhesion to the articles.
To improve the adhesion to the articles, an acrylic color coating composition is preliminarily applied as a primer coating layer, and then a polyol-based urethane coating composition is applied thereon.
Because the articles are usually exposed to the exterior environment due to the unique applications thereof, coating materials are required to show excellent ultraviolet (UV) resistance upon exposure to the exterior over long periods of time, while providing sufficient basic physical properties, including adhesion, high gloss and durability. Hence, a coating composition used as the topcoat for such articles has to show little discoloration upon exposure to UV rays over long periods of time. Conventional polyol-based urethane coating compositions have satisfied physical properties including adhesion, high gloss and durability to a certain degree. However, such conventional compositions undergo severe yellowing due to the exposure to UV rays over long periods of time, and thus have a problem related to the appearance of the articles.
Additionally, the polyol-based coating compositions tend to undergo yellowing and discoloration due to their structural characteristics. Thus, when such compositions are applied to articles, the resultant coating film may be discolored. Therefore, such compositions cannot provide a desired color.
Under these circumstances, the polyol-based coating compositions are extremely limited in their applications for surfaces of portable terminals. In other words, such coating compositions can be applied to black-colored articles that hide discoloration, but it is difficult to satisfy current demands for various colors and designs.
Further, surfaces of portable terminals coated with the conventional coating compositions show poor resistance to surface contamination. For example, when the surfaces are contaminated with pens, the contaminated portions cannot be cleaned with ease, even if the portions are treated with methyl alcohol.